So if you defragment a disk, and read a record from two different files, you could force head motion.
If many files grow the disk blocks can be allocated from the free areas, which might actually localize time dependent or associated data near each other on the disk. Except when I am all by my self on a machine, and selecting a well-tuned file, these are multi-user systems. The disk heads are never where you left them, anyway. There is often sufficient cache between you and the disk surface that it becomes difficult to tell if and when you actually do any physical I/O. Mark A. Baldridge Principal Consultant North American Lab Services DB2 Information Management, IBM Software Group (607) 351-5666 ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
